Fraud has control of my accounts and my iPhone

I was scammed into thinking I was chatting with someone I thought was a friend and they got me to add their email address to mine and now they have all control of my accounts and my iPhone. How do I remove it when I can’t even access it anymore. They’ve taken over all my social media accounts and posted a scam on my Facebook account and scammed my friend’s as well

[Re-Titled by Moderator]